User Manual
Steel Facts
WE USE SPECIFIC BLADE STEELS TO ACHIEVE A BALANCE OF PROPERTIES BASED ON THE ANTICIPATED APPLICATIONS OF THE KNIFE.
Steel is an alloy of iron, other metals and carbon. Stainless steel is a generic term for a family of corrosion-resistant alloy steels which contain 10.5% or
more chromium. “Stainless” does not mean that these alloys will never stain or corrode, but that they “stain less” than steels which do not contain chromium.
Each alloy imparts different properties to the stainless steel. The chart at the bottom of the page shows in detail what each alloy element contributes.
We use stainless steels from many international suppliers. The chart below shows within a reasonable range the equivalent qualities of comparable steels that
we use. Note that the final hardness level achieved is not only a factor of composition, but depends greatly on proper heat treatment and quenching, to which
we pay great attention.
In selecting the appropriate steel, we look at the performance requirements of the blade, the knife price range, and our manufacturing and finishing methods.
There are trade-offs. While higher alloy levels and final hardness levels keep an edge longer, they also make it more difficult to field-sharpen a blade. Some
premium alloys are low in nickel, and will stain if not kept clean and occasionally oiled after use. Consequently, we feature AUS 8 as our high-end alloy, which
has compared very well to ATS 34 in performance tests conducted by international knife magazines.
Consider these examples: A mechanic who gives his work knife hard daily use, in contact with all types of solvents and moisture, will benefit from the
durability, stain resistance and ease of sharpening found in 420J2 or AUS 4 steel. In contrast, the buyer of a CRKT Titanium M16® model expects an alloy
steel such as AUS 8 steel, with its higher hardness and edge-holding ability.
Ductility, or toughness, has its place in knives that are subjected to hard use—or even abuse—as tactical and work knives must be, and so we have selected
higher-toughness steels in many of these applications, as opposed to high-hardness steels. Based on our experience, we believe that the knife user benefits
from having the strongest and toughest blade for the application.
The blade steel and hardness range of each CRKT knife are included with its catalog specifications to make the information easier to locate.
Steel
AUS 4
AUS 8
420J2
440A
12C27 Sandvik
1.4116
6168CrV
YK-30
SK5
3Cr13
5Cr15MoV
8Cr13MoV
8Cr14MoV
9Cr18MoV
ACUTO+
Carbon
Chromium
Manganese
Molybdenum
Nickel
Silicon
Vanadium
Element
Increases
Edge
Retention
Increases
Hardness
Increases
Harden-
ability
Increases
Toughness
Increases
Tensile
Strength
Increases
Impact
Strength
Increases
Wear and
Abrasion
Resistance
Increases
Corrosion
Resistance
x x
x
x
x
x
x
x
x
x
x
x
x
x
x
x x
x
x
x
x
x
x
HRC
55-57
58-59
52-55
55-57
59-61
55-57
59-61
57-59
57-58
52-55
55-57
58-59
58-59
58-60
59-60
C
0.40-0.45
0.70-0.75
0.26-0.40
0.65-0.75
0.60
0.45-0.50
0.65-0.75
1.05
0.80-0.90
0.26-0.35
0.50
0.80
0.80
0.95-1.20
0.90-0.95
CR
13-14.5
13-14.5
12-14
16-18
13.5
14.5-14.8
0.30-0.35
0.5
--
12-14
15
13
14.07
16-18
17-18
MN
1.00
0.50
1.00
1.00
0.40
0.40
0.60
1.00
0.50
1.00
0.336
0.40
0.16
0.80
0.50
MO
--
0.10-0.30
--
0.75
--
--
--
--
--
--
0.63
0.15
0.22
0.75
1.30 to 1.50
NI
0.49
0.49
--
--
--
--
--
0.25
--
--
--
0.20
0.22
--
--
PH
0.04
0.04
0.04
0.04
0.025
0.02
0.08
0.03
0.03
0.04
0.025
0.02
0.029
0.04
0.04
SI
1.00
1.00
1.00
1.00
0.40
0.40-0.60
0.20
0.40
0.35
1.00
0.407
0.50
0.45
1.00
0.50
V
--
0.10-0.26
--
--
--
0.10-0.25
0.10-0.15
--
--
--
0.10
0.10
0.14
--
.10 to .25
CO
--
--
--
--
--
--
0.25
--
--
--
--
--
--
--
--
Stainless Steel Alloy Specifications
Benefites of Elements of Stainless Steels